Why won't high school students participate in class discussions?

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

1. 1
   Calling on students randomly
2. 2
   Having students write down answers first
3. 3
   Using elbow partners or table discussions
4. 4
   Asking weird icebreaker questions
5. 5
   Using tools like wheel of names or popsicle sticks
6. 6
   Offering a point system where participating students get their names written on the board
7. 7
   Using think-pair-share variations to give students time to think or talk with a partner
8. 8
   Letting awkward silence fill the room and waiting until someone raises their hand
9. 9
   Drawing popsicle sticks with names or using a randomizer to select students
10. 10
    Making participation part of the students' grades so that silence erodes their grades

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.